feat(browse): Puppeteer parity — load-html, screenshot --selector, viewport --scale, file:// (v1.1.0.0) (#1062)

* feat(browse): TabSession loadedHtml + command aliases + DX polish primitives

Adds the foundation layer for Puppeteer-parity features:

- TabSession.loadedHtml + setTabContent/getLoadedHtml/clearLoadedHtml —
  enables load-html content to survive context recreation (viewport --scale)
  via in-memory replay. ASCII lifecycle diagram in the source explains the
  clear-before-navigation contract.

- COMMAND_ALIASES + canonicalizeCommand() helper — single source of truth
  for name aliases (setcontent / set-content / setContent → load-html),
  consumed by server dispatch and chain prevalidation.

- buildUnknownCommandError() pure function — rich error messages with
  Levenshtein-based "Did you mean" suggestions (distance ≤ 2, input
  length ≥ 4 to skip 2-letter noise) and NEW_IN_VERSION upgrade hints.

- load-html registered in WRITE_COMMANDS + SCOPE_WRITE so scoped write
  tokens can use it.

- screenshot and viewport descriptions updated for upcoming flags.

- New browse/test/dx-polish.test.ts (15 tests): alias canonicalization,
  Levenshtein threshold + alphabetical tiebreak, short-input guard,
  NEW_IN_VERSION upgrade hint, alias + scope integration invariants.

No consumers yet — pure additive foundation. Safe to bisect on its own.

* feat(browse): accept file:// in goto with smart cwd/home-relative parsing

Extends validateNavigationUrl to accept file:// URLs scoped to safe dirs
(cwd + TEMP_DIR) via the existing validateReadPath policy. The workhorse is a
new normalizeFileUrl() helper that handles non-standard relative forms BEFORE
the WHATWG URL parser sees them:

    file:///abs/path.html       → unchanged
    file://./docs/page.html     → file://<cwd>/docs/page.html
    file://~/Documents/page.html → file://<HOME>/Documents/page.html
    file://docs/page.html       → file://<cwd>/docs/page.html
    file://localhost/abs/path   → unchanged
    file://host.example.com/... → rejected (UNC/network)
    file:// and file:///        → rejected (would list a directory)

Host heuristic rejects segments with '.', ':', '\\', '%', IPv6 brackets, or
Windows drive-letter patterns — so file://docs.v1/page.html, file://127.0.0.1/x,
file://[::1]/x, and file://C:/Users/x are explicit errors.

Uses fileURLToPath() + pathToFileURL() from node:url (never string-concat) so
URL escapes like %20 decode correctly and Node rejects encoded-slash traversal
(%2F..%2F) outright.

Signature change: validateNavigationUrl now returns Promise<string> (the
normalized URL) instead of Promise<void>. Existing callers that ignore the
return value still compile — they just don't benefit from smart-parsing until
updated in follow-up commits. Callers will be migrated in the next few commits
(goto, diff, newTab, restoreState).

Rewrites the url-validation test file: updates existing tests for the new
return type, adds 20+ new tests covering every normalizeFileUrl shape variant,
URL-encoding edge cases, and path-traversal rejection.

References: codex consult v3 P1 findings on URL parser semantics and fileURLToPath.

* feat(browse): BrowserManager deviceScaleFactor + setContent replay + file:// plumbing

Three tightly-coupled changes to BrowserManager, all in service of the
Puppeteer-parity workflow:

1. deviceScaleFactor + currentViewport tracking. New private fields (default
   scale=1, viewport=1280x720) + setDeviceScaleFactor(scale, w, h) method.
   deviceScaleFactor is a context-level Playwright option — changing it
   requires recreateContext(). The method validates (finite number, 1-3 cap,
   headed-mode rejected), stores new values, calls recreateContext(), and
   rolls back the fields on failure so a bad call doesn't leave inconsistent
   state. Context options at all three sites (launch, recreate happy path,
   recreate fallback) now honor the stored values instead of hardcoding
   1280x720.

2. BrowserState.loadedHtml + loadedHtmlWaitUntil. saveState captures per-tab
   loadedHtml from the session; restoreState replays it via newSession.
   setTabContent() — NOT bare page.setContent() — so TabSession.loadedHtml
   is rehydrated and survives *subsequent* scale changes. In-memory only,
   never persisted to disk (HTML may contain secrets or customer data).

3. newTab + restoreState now consume validateNavigationUrl's normalized
   return value. file://./x, file://~/x, and bare-segment forms now take
   effect at every navigation site, not just the top-level goto command.

Together these enable: load-html → viewport --scale 2 → viewport --scale 1.5
→ screenshot, with content surviving both context recreations. Codex v2 P0
flagged that bare page.setContent in restoreState would lose content on the
second scale change — this commit implements the rehydration path.

References: codex v2 P0 (TabSession rehydration), codex v3 P1 (4-caller
return value), plan Feature 3 + Feature 4.

* feat(browse): load-html, screenshot --selector, viewport --scale, alias dispatch

Wires the new handlers and dispatch logic that the previous commits made
possible:

write-commands.ts
- New 'load-html' case: validateReadPath for safe-dir scoping, stat-based
  actionable errors (not found, directory, oversize), extension allowlist
  (.html/.htm/.xhtml/.svg), magic-byte sniff with UTF-8 BOM strip accepting
  any <[a-zA-Z!?] markup opener (not just <!doctype — bare fragments like
  <div>...</div> work for setContent), 50MB cap via GSTACK_BROWSE_MAX_HTML_BYTES
  override, frame-context rejection. Calls session.setTabContent() so replay
  metadata is rehydrated.
- viewport command extended: optional [<WxH>], optional [--scale <n>],
  scale-only variant reads current size via page.viewportSize(). Invalid
  scale (NaN, Infinity, empty, out of 1-3) throws with named value. Headed
  mode rejected explicitly.
- clearLoadedHtml() called BEFORE goto/back/forward/reload navigation
  (not after) so a timed-out goto post-commit doesn't leave stale metadata
  that could resurrect on a later context recreation. Codex v2 P1 catch.
- goto uses validateNavigationUrl's normalized return value.

meta-commands.ts
- screenshot --selector <css> flag: explicit element-screenshot form.
  Rejects alongside positional selector (both = error), preserves --clip
  conflict at line 161, composes with --base64 at lines 168-174.
- chain canonicalizes each step with canonicalizeCommand — step shape is
  now { rawName, name, args } so prevalidation, dispatch, WRITE_COMMANDS.has,
  watch blocking, and result labels all use canonical names while audit
  labels show 'rawName→name' when aliased. Codex v3 P2 catch — prior shape
  only canonicalized at prevalidation and diverged everywhere else.
- diff command consumes validateNavigationUrl return value for both URLs.

server.ts
- Command canonicalization inserted immediately after parse, before scope /
  watch / tab-ownership / content-wrapping checks. rawCommand preserved for
  future audit (not wired into audit log in this commit — follow-up).
- Unknown-command handler replaced with buildUnknownCommandError() from
  commands.ts — produces 'Unknown command: X. Did you mean Y?' with optional
  upgrade hint for NEW_IN_VERSION entries.

security-audit-r2.test.ts
- Updated chain-loop marker from 'for (const cmd of commands)' to
  'for (const c of commands)' to match the new chain step shape. Same
  isWatching + BLOCKED invariants still asserted.

* chore: bump version and changelog (v1.1.0.0)

- VERSION: 1.0.0.0 → 1.1.0.0 (MINOR bump — new user-facing commands)
- package.json: matching version bump
- CHANGELOG.md: new 1.1.0.0 entry describing load-html, screenshot --selector,
  viewport --scale, file:// support, setContent replay, and DX polish in user
  voice with a dedicated Security section for file:// safe-dirs policy
- browse/SKILL.md.tmpl: adds pattern #12 "Render local HTML", pattern #13
  "Retina screenshots", and a full Puppeteer → browse cheatsheet with side-by-
  side API mapping and a worked tweet-renderer migration example
- browse/SKILL.md + SKILL.md: regenerated from templates via `bun run gen:skill-docs`
  to reflect the new command descriptions

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix: pre-landing review fixes (9 findings from specialist + adversarial review)

Adversarial review (Claude subagent + Codex) surfaced 9 bugs across
CRITICAL/HIGH severity. All fixed:

1. tab-session.ts:setTabContent — state mutation moved AFTER the setContent
   await. Prior order left phantom HTML in replay metadata if setContent
   threw (timeout, browser crash), which a later viewport --scale would
   silently replay. Now loadedHtml is only recorded on successful load.

2. browser-manager.ts:setDeviceScaleFactor — rollback now forces a second
   recreateContext after restoring the old fields. The fallback path in
   the original recreateContext builds a blank context using whatever
   this.deviceScaleFactor/currentViewport hold at that moment (which were
   the NEW values we were trying to apply). Rolling back the fields without
   a second recreate left the live context at new-scale while state tracked
   old-scale. Now: restore fields, force re-recreate with old values, only
   if that ALSO fails do we return a combined error.

3. commands.ts:buildUnknownCommandError — Levenshtein tiebreak simplified
   to 'd <= 2 && d < bestDist' (strict less). Candidates are pre-sorted
   alphabetically, so first equal-distance wins by default. The prior
   '(d === bestDist && best !== undefined && cand < best)' clause was dead
   code.

4. tab-session.ts:onMainFrameNavigated — now clears loadedHtml, not just
   refs + frame. Without this, a user who load-html'd then clicked a link
   (or had a form submit / JS redirect / OAuth flow) would retain the stale
   replay metadata. The next viewport --scale would silently revert the
   tab to the ORIGINAL loaded HTML, losing whatever the post-navigation
   content was. Silent data corruption. Browser-emitted navigations trigger
   this path via wirePageEvents.

5. browser-manager.ts:saveState + restoreState — tab ownership now flows
   through BrowserState.owner. Without this, a scoped agent's viewport
   --scale would strand them: tab IDs change during recreate, ownership
   map held stale IDs, owner lookup failed. New IDs had no owner, so
   writes without tabId were denied (DoS). Worse, if the agent sent a
   stale tabId the server's swallowed-tab-switch-error path would let the
   command hit whatever tab was currently active (cross-tab authz bypass).
   Now: clear ownership before restore, re-add per-tab with new IDs.

6. meta-commands.ts:state load — disk-loaded state.pages is now explicit
   allowlist (url, isActive, storage:null) instead of object spread.
   Spreading accepted loadedHtml, loadedHtmlWaitUntil, and owner from a
   user-writable state file, letting a tampered state.json smuggle HTML
   past load-html's safe-dirs / extension / magic-byte / 50MB-cap
   validators, or forge tab ownership. Now stripped at the boundary.

7. url-validation.ts:normalizeFileUrl — preserves query string + fragment
   across normalization. file://./app.html?route=home#login previously
   resolved to a filesystem path that URL-encoded '?' as %3F and '#' as
   %23, or (for absolute forms) pathToFileURL dropped them entirely. SPAs
   and fixture URLs with query params 404'd or loaded the wrong route.
   Now: split on ?/# before path resolution, reattach after.

8. url-validation.ts:validateNavigationUrl — reattaches parsed.search +
   parsed.hash to the normalized file:// URL. Same fix at the main
   validator for absolute paths that go through fileURLToPath round-trip.

9. server.ts:writeAuditEntry — audit entries now include aliasOf when the
   user typed an alias ('setcontent' → cmd: 'load-html', aliasOf:
   'setcontent'). Previously the isAliased variable was computed but
   dropped, losing the raw input from the forensic trail. Completes the
   plan's codex v3 P2 requirement.

Also added bm.getCurrentViewport() and switched 'viewport --scale'-
without-size to read from it (more reliable than page.viewportSize() on
headed/transition contexts).

Tests pass: exit 0, no failures. Build clean.

* test: integration coverage for load-html, screenshot --selector, viewport --scale, replay, aliases

Adds 28 Playwright-integration tests that close the coverage gap flagged
by the ship-workflow coverage audit (50% → expected ~80%+).

**load-html (12 tests):**
- happy path loads HTML file, page text matches
- bare HTML fragments (<div>...</div>) accepted, not just full documents
- missing file arg throws usage
- non-.html extension rejected by allowlist
- /etc/passwd.html rejected by safe-dirs policy
- ENOENT path rejected with actionable "not found" error
- directory target rejected
- binary file (PNG magic bytes) disguised as .html rejected by magic-byte check
- UTF-8 BOM stripped before magic-byte check — BOM-prefixed HTML accepted
- --wait-until networkidle exercises non-default branch
- invalid --wait-until value rejected
- unknown flag rejected

**screenshot --selector (5 tests):**
- --selector flag captures element, validates Screenshot saved (element)
- conflicts with positional selector (both = error)
- conflicts with --clip (mutually exclusive)
- composes with --base64 (returns data:image/png;base64,...)
- missing value throws usage

**viewport --scale (5 tests):**
- WxH --scale 2 produces PNG with 2x element dimensions (parses IHDR bytes 16-23)
- --scale without WxH keeps current size + applies scale
- non-finite value (abc) throws "not a finite number"
- out-of-range (4, 0.5) throws "between 1 and 3"
- missing value throws

**setContent replay across context recreation (3 tests):**
- load-html → viewport --scale 2: content survives (hits setTabContent replay path)
- double cycle 2x → 1.5x: content still survives (proves TabSession rehydration)
- goto after load-html clears replay: subsequent viewport --scale does NOT
  resurrect the stale HTML (validates the onMainFrameNavigated fix)

**Command aliases (2 tests):**
- setcontent routes to load-html via chain canonicalization
- set-content (hyphenated) also routes — both end-to-end through chain dispatch

Fixture paths use /tmp (SAFE_DIRECTORIES entry) instead of $TMPDIR which is
/var/folders/... on macOS and outside the safe-dirs boundary. Chain result
labels use rawName→name format when an alias is resolved (matches the
meta-commands.ts chain refactor).

Full suite: exit 0, 223/223 pass.

* docs: update BROWSER.md + CHANGELOG for v1.1.0.0

BROWSER.md:
- Command reference table updated: goto now lists file:// support,
  load-html added to Navigate row, viewport flagged with --scale
  option, screenshot row shows --selector + --base64 flags
- Screenshot modes table adds the fifth mode (element crop via
  --selector flag) and notes the tag-selector-not-caught-positionally
  gotcha
- New "Retina screenshots — viewport --scale" subsection explains
  deviceScaleFactor mechanics, context recreation side effects, and
  headed-mode rejection
- New "Loading local HTML — goto file:// vs load-html" subsection
  explains the two paths, their tradeoffs (URL state, relative asset
  resolution), the safe-dirs policy, extension allowlist + magic-byte
  sniff, 50MB cap, setContent replay across recreateContext, and the
  alias routing (setcontent → load-html before scope check)

CHANGELOG.md (v1.1.0.0 security section expanded, no existing content
removed):
- State files cannot smuggle HTML or forge tab ownership (allowlist
  on disk-loaded page fields)
- Audit log records aliasOf when a canonical command was reached via
  an alias (setcontent → load-html)
- load-html content clears on real navigations (clicks, form submits,
  JS redirects) — not just explicit goto. Also notes SPA query/fragment
  preservation for goto file://

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -1,5 +1,32 @@
 # Changelog
 
+## [1.1.0.0] - 2026-04-18
+
+### Added
+- **Browse can now render local HTML without an HTTP server.** Two ways: `$B goto file:///tmp/report.html` navigates to a local file (including cwd-relative `file://./x` and home-relative `file://~/x` forms, smart-parsed so you don't have to think about URL grammar), or `$B load-html /tmp/tweet.html` reads the file and loads it via `page.setContent()`. Both are scoped to cwd + temp dir for safety. If you're migrating a Puppeteer script that generates HTML in memory, this kills your Python-HTTP-server workaround.
+- **Element screenshots with an explicit flag.** `$B screenshot out.png --selector .card` is now the unambiguous way to screenshot a single element. Positional selectors still work, but tag selectors like `button` weren't recognized positionally, so the flag form fixes that. `--selector` composes with `--base64` and rejects alongside `--clip` (choose one).
+- **Retina screenshots via `--scale`.** `$B viewport 480x2000 --scale 2` sets `deviceScaleFactor: 2` and produces pixel-doubled screenshots. `$B viewport --scale 2` alone changes just the scale factor and keeps the current size. Scale is capped at 1-3 (gstack policy). Headed mode rejects the flag since scale is controlled by the real browser window.
+- **Load-HTML content survives scale changes.** Changing `--scale` rebuilds the browser context (that's how Playwright works), which previously would have wiped pages loaded via `load-html`. Now the HTML is cached in tab state and replayed into the new context automatically. In-memory only; never persisted to disk.
+- **Puppeteer → browse cheatsheet in SKILL.md.** Side-by-side table of Puppeteer APIs mapped to browse commands, plus a full worked example (tweet-renderer flow: viewport + scale + load-html + element screenshot).
+- **Guess-friendly aliases.** Type `setcontent` or `set-content` and it routes to `load-html`. Canonicalization happens before scope checks, so read-scoped tokens can't use the alias to bypass write-scope enforcement.
+- **`Did you mean ...?` on unknown commands.** `$B load-htm` returns `Unknown command: 'load-htm'. Did you mean 'load-html'?`. Levenshtein match within distance 2, gated on input length ≥ 4 so 2-letter typos don't produce noise.
+- **Rich, actionable errors on `load-html`.** Every rejection path (file not found, directory, oversize, outside safe dirs, binary content, frame context) names the input, explains the cause, and says what to do next. Extension allowlist `.html/.htm/.xhtml/.svg` + magic-byte sniff (with UTF-8 BOM strip) catches mis-renamed binaries before they render as garbage.
+
+### Security
+- `file://` navigation is now an accepted scheme in `goto`, scoped to cwd + temp dir via the existing `validateReadPath()` policy. UNC/network hosts (`file://host.example.com/...`), IP hosts, IPv6 hosts, and Windows drive-letter hosts are all rejected with explicit errors.
+- **State files can no longer smuggle HTML content.** `state load` now uses an explicit allowlist for the fields it accepts from disk — a tampered state file cannot inject `loadedHtml` to bypass the `load-html` safe-dirs, extension allowlist, magic-byte sniff, or size cap checks. Tab ownership is preserved across context recreation via the same in-memory channel, closing a cross-agent authorization gap where scoped agents could lose (or gain) tabs after `viewport --scale`.
+- **Audit log now records the raw alias input.** When you type `setcontent`, the audit entry shows `cmd: load-html, aliasOf: setcontent` so the forensic trail reflects what the agent actually sent, not just the canonical form.
+- **`load-html` content correctly clears on every real navigation** — link clicks, form submits, and JavaScript redirects now invalidate the replay metadata just like explicit `goto`/`back`/`forward`/`reload` do. Previously a later `viewport --scale` after a click could resurrect the original `load-html` content (silent data corruption). Also fixes SPA fixture URLs: `goto file:///tmp/app.html?route=home#login` preserves the query string and fragment through normalization.
+
+### For contributors
+- `validateNavigationUrl()` now returns the normalized URL (previously void). All four callers — goto, diff, newTab, restoreState — updated to consume the return value so smart-parsing takes effect at every navigation site.
+- New `normalizeFileUrl()` helper uses `fileURLToPath()` + `pathToFileURL()` from `node:url` — never string-concat — so URL escapes like `%20` decode correctly and encoded-slash traversal (`%2F..%2F`) is rejected by Node outright.
+- New `TabSession.loadedHtml` field + `setTabContent()` / `getLoadedHtml()` / `clearLoadedHtml()` methods. ASCII lifecycle diagram in the source. The `clear` call happens BEFORE navigation starts (not after) so a goto that times out post-commit doesn't leave stale metadata that could resurrect on a later context recreation.
+- `BrowserManager.setDeviceScaleFactor(scale, w, h)` is atomic: validates input, stores new values, calls `recreateContext()`, rolls back the fields on failure. `currentViewport` tracking means recreateContext preserves your size instead of hardcoding 1280×720.
+- `COMMAND_ALIASES` + `canonicalizeCommand()` + `buildUnknownCommandError()` + `NEW_IN_VERSION` are exported from `browse/src/commands.ts`. Single source of truth — both the server dispatcher and `chain` prevalidation import from the same place. Chain uses `{ rawName, name }` shape per step so audit logs preserve what the user typed while dispatch uses the canonical name.
+- `load-html` is registered in `SCOPE_WRITE` in `browse/src/token-registry.ts`.
+- Review history for the curious: 3 Codex consults (20 + 10 + 6 gaps), DX review (TTHW ~4min → <60s, Champion tier), 2 Eng review passes. Third Codex pass caught the 4-caller bug for `validateNavigationUrl` that the eng passes missed. All findings folded into the plan.
+
 ## [1.0.0.0] - 2026-04-18
 
 ### Added